From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758008AbZBLBoV (ORCPT ); Wed, 11 Feb 2009 20:44:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754719AbZBLBoI (ORCPT ); Wed, 11 Feb 2009 20:44:08 -0500 Received: from mail.suse.de ([195.135.220.2]:35776 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752763AbZBLBoF (ORCPT ); Wed, 11 Feb 2009 20:44:05 -0500 Date: Thu, 12 Feb 2009 02:43:58 +0100 From: Nick Piggin To: Peter Zijlstra Cc: Linux Kernel Mailing List , YAMAMOTO Takashi , Andrew Morton Subject: Re: [patch] mm: task dirty accounting fix Message-ID: <20090212014358.GC30043@wotan.suse.de> References: <20090210043953.GD28301@wotan.suse.de> <1234257171.23438.4.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234257171.23438.4.camel@twins> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 10, 2009 at 10:12:51AM +0100, Peter Zijlstra wrote: > On Tue, 2009-02-10 at 05:39 +0100, Nick Piggin wrote: > > Hi, > > > > This is based from an earlier patch from YAMAMOTO-san which I have > > somewhat simplified. What do you think? > > Looks nice. Was a bit surprised we never actually merged the previous > one though.. So was I, it was always in the back of my mind because I didn't want to lose a good fix. I was going to just resend it, but I decided it should actually be more consistent to do this accounting with the other ones, and the patch ended up being much smaller as a result too. But credit to YAMAMOTO san for the core fix. > > > Thanks, > > Nick > > > > -- > > YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for > > cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty). > > > > Additionally, there is some inconsistency about when task_dirty_inc is > > called. It is used for dirty balancing, however it even gets called for > > __set_page_dirty_no_writeback. > > > > So rather than increment it in a set_page_dirty wrapper, move it down to > > exactly where the dirty page accounting stats are incremented. > > > > Cc: YAMAMOTO Takashi > > Signed-off-by: Nick Piggin > > Acked-by: Peter Zijlstra > > > --- > > fs/buffer.c | 1 + > > include/linux/mm.h | 1 + > > mm/page-writeback.c | 13 +++---------- > > 3 files changed, 5 insertions(+), 10 deletions(-) > > > > Index: linux-2.6/include/linux/mm.h > > =================================================================== > > --- linux-2.6.orig/include/linux/mm.h > > +++ linux-2.6/include/linux/mm.h > > @@ -1162,6 +1162,7 @@ extern int filemap_fault(struct vm_area_ > > > > /* mm/page-writeback.c */ > > int write_one_page(struct page *page, int wait); > > +void task_dirty_inc(struct task_struct *tsk); > > > > /* readahead.c */ > > #define VM_MAX_READAHEAD 128 /* kbytes */ > > Index: linux-2.6/mm/page-writeback.c > > =================================================================== > > --- linux-2.6.orig/mm/page-writeback.c > > +++ linux-2.6/mm/page-writeback.c > > @@ -241,7 +241,7 @@ void bdi_writeout_inc(struct backing_dev > > } > > EXPORT_SYMBOL_GPL(bdi_writeout_inc); > > > > -static inline void task_dirty_inc(struct task_struct *tsk) > > +void task_dirty_inc(struct task_struct *tsk) > > { > > prop_inc_single(&vm_dirties, &tsk->dirties); > > } > > @@ -1228,6 +1228,7 @@ int __set_page_dirty_nobuffers(struct pa > > __inc_zone_page_state(page, NR_FILE_DIRTY); > > __inc_bdi_stat(mapping->backing_dev_info, > > BDI_RECLAIMABLE); > > + task_dirty_inc(current); > > task_io_account_write(PAGE_CACHE_SIZE); > > } > > radix_tree_tag_set(&mapping->page_tree, > > @@ -1263,7 +1264,7 @@ EXPORT_SYMBOL(redirty_page_for_writepage > > * If the mapping doesn't provide a set_page_dirty a_op, then > > * just fall through and assume that it wants buffer_heads. > > */ > > -static int __set_page_dirty(struct page *page) > > +int set_page_dirty(struct page *page) > > { > > struct address_space *mapping = page_mapping(page); > > > > @@ -1281,14 +1282,6 @@ static int __set_page_dirty(struct page > > } > > return 0; > > } > > - > > -int set_page_dirty(struct page *page) > > -{ > > - int ret = __set_page_dirty(page); > > - if (ret) > > - task_dirty_inc(current); > > - return ret; > > -} > > EXPORT_SYMBOL(set_page_dirty); > > > > /* > > Index: linux-2.6/fs/buffer.c > > =================================================================== > > --- linux-2.6.orig/fs/buffer.c > > +++ linux-2.6/fs/buffer.c > > @@ -628,6 +628,7 @@ static int __set_page_dirty(struct page > > __inc_zone_page_state(page, NR_FILE_DIRTY); > > __inc_bdi_stat(mapping->backing_dev_info, > > BDI_RECLAIMABLE); > > + task_dirty_inc(current); > > task_io_account_write(PAGE_CACHE_SIZE); > > } > > radix_tree_tag_set(&mapping->page_tree,